Cardiac arrhythmias can cause three types of cerebral disorders. The first, and most well-known, are strokes. The second disorder is insidious cognitive decline. Identification of cognitive decline is challenging because of the identification of the decline, the transient arrhythmia involved and the mutual link between them. The third, less well known type of cerebral disorder is psychiatric disorder. Since psychiatric disorders are less well known, characterization is difficult.
Sudden cardiac death affects 400,000 to 500,000 individuals each year in the United States and Europe. A quarter of these deaths occur in patients with no history of cardiac disease and with seemingly structurally and functionally healthy hearts.
Epidemiological data indicate that psychiatric patients, especially those with depressive and/or anxiety disorders, have a high risk of cerebro-cardiovascular events and sudden cardiac death, even in the absence of documented coronary artery disease. A prospective study of phobic anxiety in 3,000 health professionals demonstrated that the relative risk of sudden cardiac death was 6.08 times higher in this population. Weissman, M M, Markowitz, J S, Ouellette, R, Greenwald, S, Kahn, J. P (1990), Panic disorder and cardiovascular/cerebrovascular problems: Results from a community survey, Am. J. of Psychiatry, 147, (11), 1504-1508. Additionally, emotional, physiological and physical stresses are associated with increased levels of risk of cardiac arrhythmia and sudden death. In addition, unknown cardiac arrhythmia can cause brain disorders such as Cerebral Vascular Accident (CVA) or insidious cognitive deficits. Some anxiety disorders may be manifestations of true unknown or underestimated cardiac arrhythmias De Jaeger C, Jabourian A P, Findji G, Armenian G, Champart-Curie O (1994), Altered cognitive functions in a population of elderly people hospitalized for fall related fractures, J Am Geriatr. Soc. 42: 1305; Jabourian A P, de Jaeger C, Findji G, Armenian G, Haddad A (1994), Cognitive functions and fall-related fractures, Br J Psychiatry 165: 122; Jabourian A P (1995), Cognitive Functions, EEG and Gait Disorders in Cardiac Arrhythmias, One Day Before and Eight Days After Pacemaker Implantation, Ann. Med. Psychol. 153: 89-105; Jabourian A, Lancrenon S, Delva C, Perreve-Genet A, Lablanchy J-P, et al. (2014), Gait Velocity as an Indicator of Cognitive Performance in Healthy Middle-Aged Adults, PLoS ONE 9(8): e103211; see also U.S. Pat. No. 5,695,343, EP Patent Application 2661225, French Patent Application Publication 2961085, PCT Patent Publication WO2012093143, PCT Patent Publication WO2013087104.
The paroxysmal character of many cardiac arrhythmias makes arrhythmic events difficult to recognize and diagnose. A means for recording arrhythmic events with ambulatory devices or insertable loop recorders (ILR) allows cardiac monitoring over a 14 month period. However, these methods and devices to detect cardiac arrhythmias and assess the risk of potential life-threatening arrhythmia are based solely on cardiac criteria such as history or current heart disease with altered electro-cardiograms such as long PR and premature ventricular contractions. Moreover, syncope of unknown etiology and vaso-vagal syncopes with anxiety disorders are not systematically included in these criteria. Only 1% of patients meeting the cardiac criteria received an ILR. There are no guidelines for diagnosing patients complaining of anxiety disorders and “subjective” cardio-respiratory symptoms such as chest pain, difficulty breathing, palpitations and malaise, presyncope and/or syncope. In the best of cases, such patients receive standard cardiovascular tests such as EKG or ECHO, but arrhythmic events are not monitored.
These subjective symptoms are also present in a large percentage of patients suffering from panic attacks. As such, there is an unfortunate tendency for physicians to ascribe these subjective symptoms to anxiety. However, the subjective symptoms may also be manifestations of a life-threatening cardiac arrhythmia. Consequently, it is difficult to determine among psychiatric patients, especially in patients with anxiety and depressive disorders, those patients who are at risk of arrhythmia with multiple severe complications, including strokes, epilepsy, intellectual decline, dementia and sudden death.
Moreover, many psychotropic drugs are proarrhythmogenic and require a preventive rhythm study before their administration. However, the study is rarely or never done. The neuropsychiatric assessment of more than three thousands patients suffering from cardiac arrhythmia in four Parisian clinics revealed that 70% of the patients had a cognitive and walking speed decline associated with EEG disorders, falls, dizzy spells, history and/or presence of anxiodepressive disorders. These symptoms were confirmed by a corollary study.
Thus, there is a need to monitor cardiac and rhythmic patterns in patients with anxiety disorders and subjective cardio-respiratory symptoms, including chest pain, difficulty breathing, palpitations and malaise, presyncope and/or syncope, as well as other extra-cardiac pathologies in order to determine patients who are at risk of cardiac disease and arrhythmia.
The system and method of the invention can detect the risk of cardiac arrhythmia in populations who present one or more subjective disorders, or in patients with extra-cardiac pathologies. The system and method of the invention can also detect individuals at risk of cerebro-cardiovascular events such strokes, coronary and other arteries diseases, the presence or risk of cognitive impairment, and the risk of sudden cardiac death.
The invention comprises a system and method to measure and compare the walking speed of an individual depending on the individual's walking speed in order to determine the individual's propensity for the development or presence of cognitive impairment, the risks of cardiac arrhythmia, cerebral and or vascular events, and sudden cardiac death.